LTP-16N(configure)# do 
   acs              Enter acs mode
   clear            
   commit           Commit changes of configuration
   configure        Enter configuration mode
   copy             Download firmware, license, config, or upload logs, alarm 
                    history and config via TFTP, FTP, HTTP
   date             Set system date in UTC
   default          Reset to default candidate configuration
   delete           Delete
   firmware         Block of commands for working with firmware
   license          Set new license
   no               Set default setting
   ont              Ont autofind settings
   ping             Ping
   ping6            Ping for IPv6 addresses
   reboot           Reboot
   reconfigure      Reconfigure operation
   restore          Restore changes of configuration
   rollback         Rollback changes of configuration
   run              Runs a module
   save             Save configuration on NVRAM
   schedule         Operations with scheduler tasks
   send             Send command to ONT
   show             Show running and candidate configurations
   terminal         Set current session functions

LTP-16N(configure)# do save
    Configuration successfully saved to file